Concentricity gauge

cmoore806

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I just got a Sinclair concentricity gauge and put a dial indicator on it. Roughly set it up, and I will admit I didn't read the instructions but nevertheless the random round of 223/556 I grabbed from the box that I loaded yesterday was +/- 0.005. Granted my goal for this ammo is primarily 3 gun competition and we don't stretch very far out to targets usually less than 200yds.

I loaded it on a Dillon 650, what can I do short of getting a floating toolhead to help with concentricity? Is the only way to load on my Forster co-ax??
 

Fig

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Those are the very conclusions I come to. If I load on the Dillon I don't worry about it, because there's going to be some runout. If I load on the Forster I don't worry about it because there's no runout. My concentricity gage gathers dust.
 

cmoore806

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Those are the very conclusions I come to. If I load on the Dillon I don't worry about it, because there's going to be some runout. If I load on the Forster I don't worry about it because there's no runout. My concentricity gage gathers dust.
do you think that +/- 0.005 runout for 5.56 rounds shooting targets under 300 yds is okay? Probably just depends on on they perform on targets which frankly is more a problem of the man behind the gun than the concentricity. I'm only attempting to find out how much I am to blame for and how much error I can eliminate when loading ammo.
 

spife7980

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.005 isnt going to hurt a thing for what you described.

When that level of run out becomes a factor you will have blown way past needing to ask lol, its deep into the benchrest weeds.
Floaing your dies with an oring between the lock ring and the plate is an easy enough cheap quick comparison to do.
 

cmoore806

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.005 isnt going to hurt a thing for what you described.

When that level of run out becomes a factor you will have blown way past needing to ask lol, its deep into the benchrest weeds.
Floaing your dies with an oring between the lock ring and the plate is an easy enough cheap quick comparison to do.
but its +/- 0.005 for a total of 0.01. Either way I have a lee universal decapping die that came with an oring maybe I can try that, but I cant imagine it provides much in the area of auto-adjustment, may be a good experiment
 

spife7980

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but its +/- 0.005 for a total of 0.01. Either way I have a lee universal decapping die that came with an oring maybe I can try that, but I cant imagine it provides much in the area of auto-adjustment, may be a good experiment
That is a fair amount of runout...
 

LawnMM

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You're asking the wrong question. The question is: does 0.005" of run-out even matter?

Never seen shit that suggested that it did. Maybe if you're into benchrest, but that means you have to do all kinds of other gay shit that wastes time at the bench instead of on the range for risk of angering the BR God's 🤷🏼‍♂️
 
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padom

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So your TIR is .005? Or your actual runout? If .005 is your TIR then it's actually .0025.. still.not great but not terrible..match ammo the goal is .003 or less.

My match loads, whether on my 550 or 650 all see .0005-.001 TIR so my actual runout measures half that. I dont check my rounds anymore.


I use Whidden floating die toolheads all with the Uniquetek clamp kit. Forster Ultra Micrometer seating dies, Forster honed FL does for .004 under load neck diameter and set .002 neck tension with a 21st Century TiN mandrel.


What dies?
What's your brass sizing process?
The measurements above are of loaded virgin brass or fired brass you sized?
 
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AIAW

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It's a gas gun right? Fuhgeddaboudit...

Pretty sure that BCG/bolt cramming the round into the chamber at break-neck speed up the barrel extension is real gentle on them too ;) .

You should unchamber one sometime and hit it with the concentricity gauge. You'd be surprised!
 
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cmoore806

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So your TIR is .005? Or your actual runout? If .005 is your TIR then it's actually .0025.. still.not great but not terrible..match ammo the goal is .003 or less.

My match loads, whether on my 550 or 650 all see .0005-.001 TIR so my actual runout measures half that. I dont check my rounds anymore.


I use Whidden floating die toolheads all with the Uniquetek clamp kit. Forster Ultra Micrometer seating dies, Forster honed FL does for .004 under load neck diameter and set .002 neck tension with a 21st Century TiN mandrel.


What dies?
What's your brass sizing process?
The measurements above are of loaded virgin brass or fired brass you sized?
not sure what TIR means. But my runout on a single random round was 0.005 in each direction so 0.01 total. I could see it with my eyes it was such a big wobble. This is with my AR in 556. Brass is mixed range brass Mostly once fired. decapped with a lee universal decapping die wet tumbled swaged trimmed and sized. Dies in my dillon are dillon carbide dies. I admit I need to work on my fundamentals and at 100 yards I’m happy to get groups under 2MOA.
 

padom

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not sure what TIR means. But my runout on a single random round was 0.005 in each direction so 0.01 total. I could see it with my eyes it was such a big wobble. This is with my AR in 556. Brass is mixed range brass Mostly once fired. decapped with a lee universal decapping die wet tumbled swaged trimmed and sized. Dies in my dillon are dillon carbide dies. I admit I need to work on my fundamentals and at 100 yards I’m happy to get groups under 2MOA.
Ok so you did cut it in half. So your actual runout is .005. Fine fine for plinking ammo, mixed brass, dillon sizer...


TIR = Total Induced Runout which in your case is .010. That's a ton
 
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